added edge action argument

api-doc.txt

@@ -1,8 +1,21 @@
 The server listens on '/' for GET queries with a url query format like
 ?l=*&r0=*&g0=*&b0=*&a0=*&t0=* ... &rl=*&gl=*&bl=*&al=*&tl=*
+
 Where l is the number of points on a gradient. And each point of the gradient has a r* g* b* a* and t* where * is the index.
+
 r g and b are the red green and blue 8-bit colour components of a point on the gradient. A is the 5-bit global component of the led at that point.
 t is the offset from the start measured in leds.
+
 Each point also has an optional &m 'movement' argument. &m should be either -1, +1 or 0 and represents the movement per frame or the point.
-A point on the gradient can have an &m parameter, and has to have a &r, &g, &b, &a, and &t.
-The whole gradient can have a duration &d parameter and must have a length &l
+When no movement is set, 0 (no movement) is implied.
+
+When movement is set, a &e 'edge' component can also be set for that point. &e defines what the point will do once it reaches an end of the strip.
+Edge should be one of
+w to wrap to the opposite end of the strip.
+r to reverse direction
+s to stop
+
+If no &e is specified, s is implied.
+
+A point on the gradient may have a movement &m and edge &e parameter, and has to have a &r, &g, &b, &a, and &t.
+The whole gradient may have a duration &d parameter and must have a length &l

main/leds.c

@@ -0,0 +1,255 @@
+#include "leds.h"
+
+#include <stdint.h>
+#include <stddef.h>
+#include <string.h>
+#include <unistd.h>
+#include "shared.h"
+#include "esp8266/gpio_register.h"
+#include "rom/ets_sys.h"
+#include "driver/gpio.h"
+
+uint32_t g_serial_out_buffer[122];
+Led* g_leds = ((Led*)g_serial_out_buffer + 1);
+
+Gradient g_default_gradient;
+Gradient g_current_gradient;
+int g_leds_are_default = 1;
+LedsSendStatus g_leds_send_state = LEDS_SEND_WAITING;
+
+SemaphoreHandle_t g_led_mutex; // mutex governing access to data for leds
+                               // use for all global data defined in this header
+
+LedThreadData g_led_thread_data = {
+    .task = 0,
+    .func = &leds_thread
+};
+
+/// =======================================
+// leds.h internal helper functions
+/// =======================================
+
+static inline
+uint8_t lerp_uint8(uint8_t a, uint8_t b, float t) {
+    if(t <= 0) return a;
+    else if(t >= 1.0) return b;
+    else {
+        int dir = b - a;
+        return a + dir * t;
+    }
+}
+
+static inline
+void lerp_led(Led* out, const Led* from, const Led* to, float t) {
+    out->components.red = lerp_uint8(from->components.red, to->components.red, t);
+    out->components.green = lerp_uint8(from->components.green, to->components.green, t);
+    out->components.blue = lerp_uint8(from->components.blue, to->components.blue, t);
+    uint8_t glob_from = from->components.global & ~0xE0;
+    uint8_t glob_to = to->components.global & ~0xE0;
+    out->components.global = GLOBAL(lerp_uint8(glob_from, glob_to, t));
+}
+
+static inline
+void lerp_points_between(const GradientPoint from, const GradientPoint to) {
+    const int dif = to.offset - from.offset;
+    float t = 0.f;
+    for(int led = from.offset; led <= to.offset; ++led) {
+        t = (float)(led - from.offset) / (float)dif;
+        lerp_led(g_leds + led, &from.led, &to.led, t);
+    }
+}
+
+static
+void leds_config_gpio() {
+    gpio_config_t config = {
+        .intr_type = GPIO_INTR_DISABLE,
+        .mode = GPIO_MODE_OUTPUT,
+        .pin_bit_mask = 0x18030,
+        .pull_up_en = 0,
+        .pull_down_en = 0,
+    };
+    gpio_config(&config);
+}
+
+static
+void serial_write(int high) {
+    // set clock out to high, triggering a rising edge
+    gpio_set_level(CLOCK, 1);
+    // write bit to data out
+    gpio_set_level(DATA, high);
+
+    ets_delay_us(1);
+
+    // set clock to low, triggering a falling edge, shifting the LEDs shift register
+    gpio_set_level(CLOCK, 0);
+}
+
+
+/// =======================================
+// leds.h external interface functions
+/// =======================================
+
+
+void send_leds() {
+    // index of the bit being written
+    // fixed point number where the first 5 bits are the bit of a 32bit integger, and the rest is the integer
+    int write_bit = 0;
+    int write_next = 0;
+
+    gpio_set_level(CLOCK, 0);
+
+    while(write_bit < sizeof(g_serial_out_buffer) * 8) {
+        // fetch the bit being addressed
+        write_next = 0x1 & (g_serial_out_buffer[write_bit >> 5] >> (32 - (write_bit & 0x1F)));
+
+        serial_write(write_next);
+
+        write_bit++;
+    }
+
+    gpio_set_level(CLOCK, 0);
+    gpio_set_level(DATA, 0);
+
+}
+
+void set_led_range(int start, int end, Led value) {
+    for(int i = start; i < end; ++i) {
+        g_leds[i] = value;
+    }
+}
+
+void leds_set_default_gradient(const Gradient* gradient) {
+    g_default_gradient = *gradient;
+}
+
+void leds_set_current_gradient(const Gradient* gradient, int defer_send) {
+    GradientPoint from = gradient->points[0];
+    GradientPoint to;
+
+    set_led_range(0, gradient->points[0].offset, gradient->points[0].led);
+    set_led_range(gradient->points[gradient->points_len-1].offset, 120, gradient->points[gradient->points_len-1].led);
+
+    g_current_gradient = *gradient;
+
+    for(int i = 1; i < gradient->points_len; ++i) {
+        to = gradient->points[i];
+        lerp_points_between(from, to);
+        from = to;
+    }
+
+    if(!defer_send) {
+        send_leds();
+    }
+}
+
+void leds_reset_gradient(int defer_send) {
+    leds_set_current_gradient(&g_default_gradient, defer_send);
+}
+
+// swap to ranges of memory using a temporary block
+static
+void memswap(void* d, void* s, size_t n) {
+    void* tmp = malloc(n);
+    memcpy(tmp, s, n);
+    memcpy(s, d, n);
+    memcpy(d, tmp, n);
+    free(tmp);
+}
+
+static
+void led_check_edge(GradientPoint* point) {
+    int offset = clamp(point->offset, 0, 120);
+    switch(point->edge_action) {
+        default:
+        case LEDS_EDGE_WRAP:
+            if(point->offset < 0) {
+                point->offset += 120;
+            } else if(point->offset >= 120) {
+                point->offset %= 120;
+            }
+        break;
+        case LEDS_EDGE_REVERSE: {
+            if(offset != point->offset) {
+                point->offset = offset;
+                point->movement *= -1;
+            }
+            break;
+        }
+        case LEDS_EDGE_STOP:
+            point->offset = clamp(point->offset, 0, 120);
+        break;
+    }
+}
+
+void leds_animate() {
+    for(size_t i = 0; i < g_current_gradient.points_len; ++i) {
+        // The gradient point at i
+        GradientPoint* point = g_current_gradient.points + i;
+        // move towards end
+        if(point->movement > 0) {
+            ++point->offset;
+            // without moving past it
+            led_check_edge(point);
+            // swap with next point if we pass it
+            if(point->offset > (point+1)->offset) {
+                memswap(point, point+1, sizeof(GradientPoint));
+            }
+        // move towards start
+        } else if(point->movement < 0) {
+            ++point->offset;
+            // without passing it
+            led_check_edge(point);
+
+            // swap with previous point if we fall below it
+            if(point->offset < (point-1)->offset) {
+                memswap(point, point-1, sizeof(GradientPoint));
+            }
+        }
+    }
+    leds_set_current_gradient(&g_current_gradient, 1);
+}
+
+void leds_thread() {
+    send_leds();
+    float timer = 0;
+    for(;;) {
+        // wait for 10 milliseconds,
+        // giving FreeRTOS time to run other tasks
+        vTaskDelay(10 / portTICK_RATE_MS);
+        // tick timer by 10ms
+        timer += 0.01;
+        xSemaphoreTake(g_led_mutex, portMAX_DELAY);
+        {
+            send_leds();
+            leds_animate();
+
+            // reset gradient, defer send until next frame
+            if(timer > g_current_gradient.duration) {
+                timer = 0.f;
+                leds_reset_gradient(1);
+            }
+        }
+        xSemaphoreGive(g_led_mutex);
+    }
+}
+
+void leds_init() {
+    g_serial_out_buffer[0] = 0u;
+    g_serial_out_buffer[61] = ~0u;
+    set_led_range(0, 120,
+        (Led){.components = 
+        (LedComponents) {
+            .red = 0,
+            .green = 0,
+            .blue = 0,
+            .global = GLOBAL(5)
+        }}
+    );
+
+    g_led_mutex = xSemaphoreCreateMutex();
+
+    xTaskCreate(g_led_thread_data.func, "Leds", 1024, NULL, 1, &g_led_thread_data.task);
+
+    // initialize mutex for leds data
+    leds_config_gpio();
+}

main/leds.h

@@ -8,259 +8,80 @@
 #define _potion_leds_h
 
 #include <FreeRTOS.h>
-#include <stdint.h>
-#include <stddef.h>
-#include <unistd.h>
-#include "shared.h"
-#include "esp8266/gpio_register.h"
+#include <freertos/task.h>
+#include <freertos/semphr.h>
 #include "esp_system.h"
-#include "rom/ets_sys.h"
-#include "driver/gpio.h"
 
-enum leds_send_state_t {
+typedef enum LedsSendStatus {
     LEDS_SEND_WAITING,
     LEDS_SEND_REQUESTED,
     LEDS_SENDING,
-};
+} LedsSendStatus;
+
+typedef enum MoveEdgeAction {
+    LEDS_EDGE_WRAP,
+    LEDS_EDGE_REVERSE,
+    LEDS_EDGE_STOP
+} MoveEdgeAction;
 
 // pack the struct to match exactly 8 * 4 = 32bits
-struct __attribute__((__packed__)) led_components_t {
+typedef struct __attribute__((__packed__)) LedComponents {
     // RGB component values
     uint8_t red;
     uint8_t green;
     uint8_t blue;
     uint8_t global; // global baseline brightness, highest 3 bits should always be ones
-};
+} LedComponents;
 
 // union of components and their representation as a u32
 // allows for easier sending of data over serial
-union led_t {
-    struct led_components_t components;
+typedef union Led {
+    struct LedComponents components;
     uint32_t bits;
-};
+} Led;
 
 // point on a gradient
-struct gradient_point_t {
-    union led_t led;    // value of the led at this point
-    size_t offset;      // offset (measured in leds) from the beginning
+typedef struct GradientPoint {
+    union Led led;    // value of the led at this point
+    int offset;      // offset (measured in leds) from the beginning
     short movement;     // direction of movement over time
-};
+    MoveEdgeAction edge_action; // what to do when movement hits an end of the strip
+} GradientPoint;
 
-struct gradient_t {
-    struct gradient_point_t points[16]; // array of gradient points, support at most 16 points in a gradient
+typedef struct Gradient {
+    struct GradientPoint points[16]; // array of gradient points, support at most 16 points in a gradient
     size_t points_len;                           // number of used gradient points
     float duration;                       // amount of time to allow this gradient to last
                                           // positive means an amount in second 0 or negative means indefinitely until further notice
-};
+} Gradient;
+
+typedef struct LedThreadData {
+    TaskHandle_t task;
+    TaskFunction_t func;
+} LedThreadData;
 
 // buffer that will be written out to the led strip over serial
-uint32_t g_serial_out_buffer[122];
+extern uint32_t g_serial_out_buffer[122];
 // 120-long slice of the out buffer that represents the first few leds
-union led_t* g_leds = ((union led_t*)g_serial_out_buffer + 1);
-
-struct gradient_t g_default_gradient;
-struct gradient_t g_current_gradient;
-int g_leds_are_default = 1;
-enum leds_send_state_t g_leds_send_state = LEDS_SEND_WAITING;
-
-SemaphoreHandle_t g_led_mutex; // mutex governing access to data for leds
-                               // use for all global data defined in this header
+extern Led* g_leds;
+extern Gradient g_default_gradient;
+extern Gradient g_current_gradient;
+extern int g_leds_are_default;
+extern enum LedsSendStatus g_leds_send_state;
+extern SemaphoreHandle_t g_led_mutex;
+extern LedThreadData g_led_thread_data;
 
 #define CLOCK 4
 #define DATA 5
 
-static
-void leds_config_gpio() {
-    gpio_config_t config = {
-        .intr_type = GPIO_INTR_DISABLE,
-        .mode = GPIO_MODE_OUTPUT,
-        .pin_bit_mask = 0x18030,
-        .pull_up_en = 0,
-        .pull_down_en = 0,
-    };
-    gpio_config(&config);
-    
-}
+extern void send_leds();
 
-static
-void serial_write(int high) {
-    // set clock out to high, triggering a rising edge
-    gpio_set_level(CLOCK, 1);
-    // write bit to data out
-    gpio_set_level(DATA, high);
+extern void set_led_range(int start, int end, Led value);
+extern void leds_set_default_gradient(const Gradient* gradient);
+extern void leds_set_current_gradient(const Gradient* gradient, int defer_send);
+extern void leds_reset_gradient(int defer_send);
 
-    ets_delay_us(1);
-
-    // set clock to low, triggering a falling edge, shifting the LEDs shift register
-    gpio_set_level(CLOCK, 0);
-}
-
-static
-void send_leds() {
-    // index of the bit being written
-    // fixed point number where the first 5 bits are the bit of a 32bit integger, and the rest is the integer
-    int write_bit = 0;
-    int write_next = 0;
-
-    gpio_set_level(CLOCK, 0);
-
-    while(write_bit < sizeof(g_serial_out_buffer) * 8) {
-        // fetch the bit being addressed
-        write_next = 0x1 & (g_serial_out_buffer[write_bit >> 5] >> (32 - (write_bit & 0x1F)));
-
-        serial_write(write_next);
-
-        write_bit++;
-    }
-
-    gpio_set_level(CLOCK, 0);
-    gpio_set_level(DATA, 0);
-
-}
-
-static inline
-uint8_t lerp_uint8(uint8_t a, uint8_t b, float t) {
-    if(t <= 0) return a;
-    else if(t >= 1.0) return b;
-    else {
-        int dir = b - a;
-        return a + dir * t;
-    }
-}
-
-static inline
-void lerp_led(union led_t* out, const union led_t* from, const union led_t* to, float t) {
-    out->components.red = lerp_uint8(from->components.red, to->components.red, t);
-    out->components.green = lerp_uint8(from->components.green, to->components.green, t);
-    out->components.blue = lerp_uint8(from->components.blue, to->components.blue, t);
-    uint8_t glob_from = from->components.global & ~0xE0;
-    uint8_t glob_to = to->components.global & ~0xE0;
-    out->components.global = GLOBAL(lerp_uint8(glob_from, glob_to, t));
-}
-
-static inline
-void lerp_points_between(const struct gradient_point_t from, const struct gradient_point_t to) {
-    const int dif = to.offset - from.offset;
-    float t = 0.f;
-    for(int led = from.offset; led <= to.offset; ++led) {
-        t = (float)(led - from.offset) / (float)dif;
-        lerp_led(g_leds + led, &from.led, &to.led, t);
-    }
-}
-
-static
-void set_led_range(int start, int end, union led_t value) {
-    for(int i = start; i < end; ++i) {
-        g_leds[i] = value;
-    }
-}
-
-static
-void leds_set_default_gradient(const struct gradient_t* gradient) {
-    g_default_gradient = *gradient;
-}
-
-static
-void leds_set_current_gradient(const struct gradient_t* gradient, int defer_send) {
-    struct gradient_point_t from = gradient->points[0];
-    struct gradient_point_t to;
-
-    set_led_range(0, gradient->points[0].offset, gradient->points[0].led);
-    set_led_range(gradient->points[gradient->points_len-1].offset, 120, gradient->points[gradient->points_len-1].led);
-
-    g_current_gradient = *gradient;
-
-    for(int i = 1; i < gradient->points_len; ++i) {
-        to = gradient->points[i];
-        lerp_points_between(from, to);
-        from = to;
-    }
-
-    if(!defer_send) {
-        send_leds();
-    }
-}
-
-void memswap(void* d, void* s, size_t n) {
-    void* tmp = malloc(n);
-    memcpy(tmp, s, n);
-    memcpy(s, d, n);
-    memcpy(d, tmp, n);
-    free(tmp);
-}
-
-void leds_animate() {
-    for(size_t i = 0; i < g_current_gradient.points_len; ++i) {
-        struct gradient_point_t* point = g_current_gradient.points + i;
-        if(point->movement > 0) {
-            point->offset = min(point->offset + 1, 120);
-            LOGLN("move result %i", point->offset);
-            LOGLN("next %d", (point+1)->offset);
-
-            if(point->offset > (point+1)->offset) {
-                memswap(point, point+1, sizeof(struct gradient_point_t));
-                LOGLN("swap down");
-            }
-        } else if(point->movement < 0) {
-            point->offset = max(0, point->offset - 1);
-            LOGLN("move result %i", point->offset);
-            LOGLN("next %d", (point-1)->offset);
-
-            if(point->offset < (point-1)->offset) {
-                memswap(point, point-1, sizeof(struct gradient_point_t));
-                LOGLN("swap up");
-            }
-        }
-    }
-    leds_set_current_gradient(&g_current_gradient, 1);
-}
-
-struct led_thread_data_t {
-    TaskHandle_t task;
-    TaskFunction_t func;
-};
-
-static void leds_thread();
-
-static struct led_thread_data_t _thread_data = {
-    .task = 0,
-    .func = &leds_thread
-};
-
-static
-void leds_thread() {
-    send_leds();
-    for(;;) {
-        vTaskDelay(10);
-        xSemaphoreTake(g_led_mutex, portMAX_DELAY);
-        send_leds();
-        leds_animate();
-        xSemaphoreGive(g_led_mutex);
-    }
-}
-
-
-
-static
-void leds_init() {
-    g_serial_out_buffer[0] = 0u;
-    g_serial_out_buffer[61] = ~0u;
-    set_led_range(0, 120,
-        (union led_t){.components = 
-        (struct led_components_t) {
-            .red = 0,
-            .green = 0,
-            .blue = 0,
-            .global = GLOBAL(5)
-        }}
-    );
-
-    g_led_mutex = xSemaphoreCreateMutex();
-
-    xTaskCreate(_thread_data.func, "Leds", 1024, NULL, 1, &_thread_data.task);
-
-    // initialize mutex for leds data
-    leds_config_gpio();
-}
+extern void leds_thread();
+extern void leds_init();
 
 #endif // !_leds_h

main/network.c

@@ -0,0 +1,66 @@
+#include "network.h"
+
+#include "shared.h"
+#include "parse.h"
+#include <string.h>
+#include <esp_wifi.h>
+#include <esp_wifi_types.h>
+#include <esp_event.h>
+
+static
+void on_station_connects(wifi_event_ap_staconnected_t* event) {
+    LOGLN("Station %d connected", event->aid);
+}
+
+static
+void on_station_disconnects(wifi_event_ap_stadisconnected_t* event) {
+    LOGLN("Station %d disconnected", event->aid);
+}
+
+static
+void on_wifi_event(void* arg, esp_event_base_t event_base,
+                   int32_t event_id, void* event_data) {
+    switch(event_id) {
+        case WIFI_EVENT_AP_STACONNECTED:
+            on_station_connects(event_data);
+            break;
+        case WIFI_EVENT_AP_STADISCONNECTED:
+            on_station_disconnects(event_data);
+            break;
+    }
+}
+
+void wifi_init() {
+    LOGLN("Configuring WIFI");
+    // init tcp/ip stack
+    tcpip_adapter_init();
+    // initialize wifi
+    wifi_init_config_t wifi_startup = WIFI_INIT_CONFIG_DEFAULT();
+    ESP_ERROR_CHECK(esp_wifi_init(&wifi_startup));
+    ESP_ERROR_CHECK(esp_event_handler_register(WIFI_EVENT, ESP_EVENT_ANY_ID, &on_wifi_event, NULL));
+    LOGLN("WiFi initialized");
+}
+
+void softap_init() {
+    LOGLN("Starting wireless Access Point");
+    // set mode to wifi
+    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_AP));
+
+    // configure wifi hardware to serve as a wifi access point
+    wifi_config_t accesspoint_startup_config = {
+      .ap = {
+            .ssid = SSID,
+            .ssid_len = strlen(SSID),
+            .password = PASSW,
+            .max_connection=32,
+            .authmode = WIFI_AUTH_WPA_WPA2_PSK
+        }
+    };
+
+    // configure with created startup config
+    ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_AP, &accesspoint_startup_config));
+    // start wifi access point
+    ESP_ERROR_CHECK(esp_wifi_start());
+
+    LOGLN("Opened AP SSID: \"%s\" PW: \"%s\"", SSID, PASSW);
+}

main/network.h

@@ -5,71 +5,10 @@
 //
 ///
 
-#ifndef _server_h
-#define _server_h
+#ifndef _potion_party_network_h
+#define _potion_party_network_h
 
-#include "esp_wifi_types.h"
-#include "shared.h"
-#include "esp_event.h"
+void wifi_init();
+void softap_init();
 
-static
-void on_station_connects(wifi_event_ap_staconnected_t* event) {
-    LOGLN("Station %d connected", event->aid);
-}
-
-static
-void on_station_disconnects(wifi_event_ap_stadisconnected_t* event) {
-    LOGLN("Station %d disconnected", event->aid);
-}
-
-static
-void on_wifi_event(void* arg, esp_event_base_t event_base,
-                   int32_t event_id, void* event_data) {
-    switch(event_id) {
-        case WIFI_EVENT_AP_STACONNECTED:
-            on_station_connects(event_data);
-            break;
-        case WIFI_EVENT_AP_STADISCONNECTED:
-            on_station_disconnects(event_data);
-            break;
-    }
-}
-
-static inline
-void wifi_init() {
-    LOGLN("Configuring WIFI");
-    // init tcp/ip stack
-    tcpip_adapter_init();
-    // initialize wifi
-    wifi_init_config_t wifi_startup = WIFI_INIT_CONFIG_DEFAULT();
-    ESP_ERROR_CHECK(esp_wifi_init(&wifi_startup));
-    ESP_ERROR_CHECK(esp_event_handler_register(WIFI_EVENT, ESP_EVENT_ANY_ID, &on_wifi_event, NULL));
-    LOGLN("WiFi initialized");
-}
-
-static inline
-void softap_init() {
-    LOGLN("Starting wireless Access Point");
-    // set mode to wifi
-    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_AP));
-
-    // configure wifi hardware to serve as a wifi access point
-    wifi_config_t accesspoint_startup_config = {
-      .ap = {
-            .ssid = SSID,
-            .ssid_len = strlen(SSID),
-            .password = PASSW,
-            .max_connection=32,
-            .authmode = WIFI_AUTH_WPA_WPA2_PSK
-        }
-    };
-
-    // configure with created startup config
-    ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_AP, &accesspoint_startup_config));
-    // start wifi access point
-    ESP_ERROR_CHECK(esp_wifi_start());
-
-    LOGLN("Opened AP SSID: \"%s\" PW: \"%s\"", SSID, PASSW);
-}
-
-#endif // !_server_h
+#endif

main/parse.c

@@ -0,0 +1,112 @@
+#include "shared.h"
+#include "leds.h"
+#include <string.h>
+#include <esp_http_server.h>
+
+MoveEdgeAction strtoea(const char* str) {
+    if(strcmp(str, "w")) {
+        return LEDS_EDGE_WRAP;
+    } else if(strcmp(str, "r")) {
+        return LEDS_EDGE_REVERSE;
+    } else {
+        return LEDS_EDGE_STOP;
+    }
+}
+
+// parse a URL query as described in api-doc.txt into a valid Gradient struct.
+// If the gradient is invalid, the is_ok flag on the return value will be set, and error will be set to a message describing the problem.
+Result parse_leds_query(char* query_string, size_t query_size) {
+    char query_value[16];
+    char query_key[3];
+    Gradient* gradient = malloc(sizeof(Gradient));
+
+    // Fetch the &l length parameter.
+    // Interpret as a positive integer number of points on the gradient.
+    if(httpd_query_key_value(query_string, "l", query_value, sizeof(query_value)) == ESP_OK) {
+        gradient->points_len = max(0, atoi(query_value));
+    } else {
+        free(gradient);
+        return PARSE_ERR("ERROR: Failed to find length parameter &l");
+    }
+
+    // Get the &d 'duration' parameter from the query.
+    // Interpreted as a floating point number of seconds before returning to default state.
+    if(httpd_query_key_value(query_string, "d", query_value, sizeof(query_value)) == ESP_OK) {
+        gradient->duration = atof(query_string);
+    } else {
+        gradient->duration = 0;
+    }
+
+    LOGLN("Reading %zu points of gradient query:", gradient->points_len);
+    LOGLN("duration: %f", gradient->duration);
+
+    // Get the gradient point components for every point that was promised by the &l parameter
+    for(int point = 0; point < gradient->points_len; ++point) {
+        // Get the r, g, and b components as 8 bit integers
+        sprintf(query_key, "r%d", point);
+        if(httpd_query_key_value(query_string, query_key, query_value, sizeof(query_size)) == ESP_OK) {
+            gradient->points[point].led.components.red = atoi(query_value);
+        } else {
+            free(gradient);
+            return PARSE_ERR("ERROR: Point missing red component &r.");
+        }
+        sprintf(query_key, "g%d", point);
+        if(httpd_query_key_value(query_string, query_key, query_value, sizeof(query_size)) == ESP_OK) {
+            gradient->points[point].led.components.green = atoi(query_value);
+        } else {
+            free(gradient);
+            return PARSE_ERR("ERROR: Point missing green component &g.");
+        }
+        sprintf(query_key, "b%d", point);
+        if(httpd_query_key_value(query_string, query_key, query_value, sizeof(query_value)) == ESP_OK) {
+            gradient->points[point].led.components.blue = atoi(query_value);
+        } else {
+            free(gradient);
+            return PARSE_ERR("ERROR: Point missing blue component &b.");
+        }
+        // Get the global variable, passed as alpha. Limited to 0-32 (a 5bit unsigned int)
+        // Make sure the most significant 3 bits are all ones
+        sprintf(query_key, "a%d", point);
+        if(httpd_query_key_value(query_string, query_key, query_value, sizeof(query_value)) == ESP_OK) {
+            gradient->points[point].led.components.global = GLOBAL((uint8_t)atoi(query_value));
+        } else {
+            free(gradient);
+            return PARSE_ERR("ERROR: Point missing alpha component &a.");
+        }
+        // Get the time of the gradient as a number ranging from 0 - 120.
+        // Interpreted as an integer offset from the first led to the last
+        sprintf(query_key, "t%d", point);
+        if(httpd_query_key_value(query_string, query_key, query_value, sizeof(query_value)) == ESP_OK) {
+            gradient->points[point].offset = clamp(0, 120, atoi(query_value));
+        } else {
+            free(gradient);
+            return PARSE_ERR("ERROR: Point missing time component &t.");
+        }
+        // Get the movement variable &m.
+        // Interpreted as an integer number from -1 to +1
+        sprintf(query_key, "m%d", point);
+        if(httpd_query_key_value(query_string, query_key, query_value, sizeof(query_value)) == ESP_OK) {
+            gradient->points[point].movement = clamp(-1, +1, atoi(query_value));
+        } else {
+            gradient->points[point].movement = 0;
+        }
+        sprintf(query_key, "e%d", point);
+        if(httpd_query_key_value(query_string, query_key, query_value, sizeof(query_value)) == ESP_OK) {
+            gradient->points[point].edge_action = strtoea(query_value);
+        } else {
+            gradient->points[point].edge_action = LEDS_EDGE_STOP;
+        }
+
+        // Log fetched fields
+        LOGLN("led[%d]:", point);
+        LOGLN("    r %d", gradient->points[point].led.components.red);
+        LOGLN("    g %d", gradient->points[point].led.components.green);
+        LOGLN("    b %d", gradient->points[point].led.components.blue);
+        LOGLN("    global %d", gradient->points[point].led.components.global >> 3);
+        // may show up as a compile error on modern computers,
+        // x86_64 size_t is usually an unsigned long int, on the ESP8266 it is an unsigned int
+        LOGLN("    t %u", gradient->points[point].offset);
+    }
+
+    return PARSE_OK(gradient);
+}

main/parse.h

@@ -0,0 +1,9 @@
+#ifndef _potion_party_parse_h
+#define _potion_party_parse_h
+
+#include "shared.h"
+#include <stddef.h>
+
+extern Result parse_leds_query(char* query_string, size_t query_size);
+
+#endif

main/potion_party.c

@@ -3,8 +3,13 @@
 #include "network.h"
 #include "server.h"
 #include "rom/ets_sys.h"
+#include "esp_system.h"
+#include "esp_netif.h"
+#include "esp_event.h"
 
 #include <stdio.h>
+#include <stddef.h>
+#include <stdlib.h>
 #include <string.h>
 
 // starts the basic subsystems we will be using
@@ -21,7 +26,7 @@ void TEST_leds() {
     // TEST: after a delay, set the leds to a gradient of red - black
     sleep(1);
 
-    union led_t led = {
+    Led led = {
         .components = {
             .red = 0,
             .green = 255,
@@ -37,12 +42,12 @@ void TEST_leds() {
 
     sleep(1);
 
-    struct gradient_t gradient;
+    Gradient gradient;
     gradient.points_len = 4;
 
     gradient.points[0].offset = 0;
     gradient.points[0].movement = 0;
-    gradient.points[0].led.components = (struct led_components_t) {
+    gradient.points[0].led.components = (LedComponents) {
         .global = GLOBAL(0),
         .red = 0,
         .green = 0,
@@ -51,7 +56,7 @@ void TEST_leds() {
 
     gradient.points[1].offset = 59;
     gradient.points[1].movement = -1;
-    gradient.points[1].led.components = (struct led_components_t){
+    gradient.points[1].led.components = (LedComponents){
         .global = GLOBAL(10),
         .red = 40,
         .green = 200,
@@ -59,7 +64,7 @@ void TEST_leds() {
     };
     gradient.points[2].offset = 61;
     gradient.points[2].movement = 1;
-    gradient.points[2].led.components = (struct led_components_t){
+    gradient.points[2].led.components = (LedComponents){
         .global = GLOBAL(10),
         .red = 40,
         .green = 200,
@@ -67,7 +72,7 @@ void TEST_leds() {
     };
     gradient.points[3].offset = 120;
     gradient.points[3].movement = 0;
-    gradient.points[3].led.components = (struct led_components_t){
+    gradient.points[3].led.components = (LedComponents){
         .global = GLOBAL(0),
         .red = 0,
         .green = 0,

main/server.c

@@ -0,0 +1,124 @@
+#include "server.h"
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include "shared.h"
+#include "leds.h"
+#include "parse.h"
+#include <esp_http_server.h>
+#include <esp_system.h>
+#include <esp_netif.h>
+#include <sys_arch.h>
+
+const char* http_response_ok = "OK!";
+static httpd_handle_t g_http_server = NULL;
+
+// convert a (valid) request as described in api-doc.txt to a gradient.
+static
+Result request_to_gradient(httpd_req_t* request) {
+    // buffer for query string
+    char* query_buffer;
+    size_t query_length = httpd_req_get_url_query_len(request) + 1;
+
+    Result result = { .error = NULL };
+
+    if(query_length > 1) {
+        query_buffer = malloc(query_length * sizeof(char));
+        if(httpd_req_get_url_query_str(request, query_buffer, query_length) == ESP_OK) {
+            LOGLN("Received query.");
+            result = parse_leds_query(query_buffer, query_length);
+        }
+        free(query_buffer);
+    }
+
+    return result;    
+}
+
+// receives HTTP GET requests on root
+static 
+esp_err_t on_http_get_root(httpd_req_t* request) {
+    const char* response_msg = http_response_ok;
+    LOGLN("GET received on '/next'.");
+    // convert the request url to a gradient
+    Result result = request_to_gradient(request);
+    // an error was returned, pass it on to the API caller
+    if(!result.is_ok) {
+        httpd_resp_set_status(request, "400 Bad Request");
+        response_msg = result.error;
+    } else {
+        // grab a lock on the leds data
+        xSemaphoreTake(g_led_mutex, portMAX_DELAY);
+        // modify leds data, defer sending for the leds thread to take care of
+        leds_set_current_gradient(result.ok, 1);
+        // release lock
+        xSemaphoreGive(g_led_mutex);
+        // request to gradient allocates the gradient on the heap,
+        // we can free that after use
+        free(result.ok);
+    }
+    // respond to http caller
+    httpd_resp_send(request, response_msg, strlen(response_msg));
+    return ESP_OK;
+}
+httpd_uri_t get_root_uri = {
+    .uri="/",
+    .method=HTTP_GET,
+    .handler=&on_http_get_root,
+    .user_ctx = NULL
+};
+
+static
+esp_err_t on_http_get_default(httpd_req_t* request) {
+    const char* response_msg = http_response_ok;
+    LOGLN("GET received on '/default'.");
+    // convert the request to a gradient object
+    Result result = request_to_gradient(request);
+    // handle invalid query
+    if(!result.is_ok) {
+        httpd_resp_set_status(request, "400 Bad Request");
+        response_msg = result.error;
+    } else {
+        // set default gradient
+        // take lock on leds data
+        xSemaphoreTake(g_led_mutex, portMAX_DELAY);
+        leds_set_default_gradient(result.ok);
+        // release lock on leds data
+        xSemaphoreGive(g_led_mutex);
+        // we allocated a gradient_t struct with request_to_gradient,
+        // we no longer need it so we'll free it asap
+        free(result.ok);
+    }
+    // send http response
+    httpd_resp_send(request, response_msg, strlen(response_msg));
+    return ESP_OK;
+}
+httpd_uri_t get_default_uri = {
+    .uri="/default",
+    .method=HTTP_GET,
+    .handler=&on_http_get_default,
+    .user_ctx=NULL
+};
+
+// Configure server and enable the http handler.
+static
+httpd_handle_t start_webserver(void) {
+    httpd_handle_t server = NULL;
+    httpd_config_t server_config = HTTPD_DEFAULT_CONFIG();
+
+    LOGLN("Starting HTTPd server ':%d'.", server_config.server_port);
+
+    if(httpd_start(&server, &server_config) == ESP_OK) {
+        httpd_register_uri_handler(server, &get_root_uri);
+        httpd_register_uri_handler(server, &get_default_uri);
+        return server;
+    }
+
+    LOGLN("Failed to start HTTPd server.");
+    return NULL;
+}
+
+// Start an http server and store it's handle in g_http_server.
+void server_init(void) {
+    g_http_server = start_webserver();
+}

main/server.h

@@ -14,189 +14,6 @@
 #ifndef _potion_party_server_h
 #define _potion_party_server_h
 
-#include <stddef.h>
-#include <stdlib.h>
-#include <string.h>
-#include "shared.h"
-#include "leds.h"
-#include "esp_http_server.h"
-#include "esp_system.h"
-#include "esp_netif.h"
-#include "sys_arch.h"
-
-static
-httpd_handle_t g_http_server = NULL;
-
-struct parse_error_t {
-    const char* error;
-};
-
-// Parse a gradient query
-static
-struct parse_error_t parse_leds_query(char* query_string, size_t query_size) {
-    char query_value[16];
-    char query_key[3];
-    struct gradient_t gradient;
-
-    // Fetch the &l length parameter.
-    // Interpret as a positive integer number of points on the gradient.
-    if(httpd_query_key_value(query_string, "l", query_value, sizeof(query_value)) == ESP_OK) {
-        gradient.points_len = max(0, atoi(query_value));
-    } else {
-        leds_set_current_gradient(&g_default_gradient, 0);
-        return (struct parse_error_t) {
-            .error = "ERROR: Failed to find length parameter &l"
-        };
-    }
-
-    // Get the &d 'duration' parameter from the query.
-    // Interpreted as a floating point number of seconds before returning to default state.
-    if(httpd_query_key_value(query_string, "d", query_value, sizeof(query_value)) == ESP_OK) {
-        gradient.duration = atof(query_string);
-    } else {
-        gradient.duration = 0;
-    }
-
-    LOGLN("Reading %zu points of gradient query:", gradient.points_len);
-    LOGLN("duration: %f", gradient.duration);
-
-    // Get the gradient point components for every point that was promised by the &l parameter
-    for(int point = 0; point < gradient.points_len; ++point) {
-        // Get the r, g, and b components as 8 bit integers
-        sprintf(query_key, "r%d", point);
-        if(httpd_query_key_value(query_string, query_key, query_value, sizeof(query_size)) == ESP_OK) {
-            gradient.points[point].led.components.red = atoi(query_value);
-        } else {
-            return (struct parse_error_t) {
-                .error = "ERROR: Point missing red component &r."
-            };
-        }
-        sprintf(query_key, "g%d", point);
-        if(httpd_query_key_value(query_string, query_key, query_value, sizeof(query_size)) == ESP_OK) {
-            gradient.points[point].led.components.green = atoi(query_value);
-        } else {
-            return (struct parse_error_t) {
-                .error = "ERROR: Point missing green component &g."
-            };
-        }
-        sprintf(query_key, "b%d", point);
-        if(httpd_query_key_value(query_string, query_key, query_value, sizeof(query_value)) == ESP_OK) {
-            gradient.points[point].led.components.blue = atoi(query_value);
-        } else {
-            return (struct parse_error_t) {
-                .error = "ERROR: Point missing blue component &b."
-            };
-        }
-        // Get the global variable, passed as alpha. Limited to 0-32 (a 5bit unsigned int)
-        // Make sure the most significant 3 bits are all ones
-        sprintf(query_key, "a%d", point);
-        if(httpd_query_key_value(query_string, query_key, query_value, sizeof(query_value)) == ESP_OK) {
-            gradient.points[point].led.components.global = GLOBAL((uint8_t)atoi(query_value));
-        } else {
-            return (struct parse_error_t) {
-                .error = "ERROR: Point missing alpha component &a."
-            };
-        }
-        // Get the time of the gradient as a number ranging from 0 - 120.
-        // Interpreted as an integer offset from the first led to the last
-        sprintf(query_key, "t%d", point);
-        if(httpd_query_key_value(query_string, query_key, query_value, sizeof(query_value)) == ESP_OK) {
-            gradient.points[point].offset = clamp(0, 120, atoi(query_value));
-        } else {
-            return (struct parse_error_t) {
-                .error = "ERROR: Point missing time component &t."
-            };
-        }
-        // Get the movement variable &m.
-        // Interpreted as an integer number from -1 to +1
-        sprintf(query_key, "m%d", point);
-        if(gradient.duration > 0 && httpd_query_key_value(query_string, query_key, query_value, sizeof(query_value)) == ESP_OK) {
-            gradient.points[point].movement = clamp(-1, +1, atoi(query_value));
-        } else {
-            gradient.points[point].movement = 0;
-        }
-
-        // Log fetched fields
-        LOGLN("led[%d]:", point);
-        LOGLN("    r %d", gradient.points[point].led.components.red);
-        LOGLN("    g %d", gradient.points[point].led.components.green);
-        LOGLN("    b %d", gradient.points[point].led.components.blue);
-        LOGLN("    global %d", gradient.points[point].led.components.global >> 3);
-        // may show up as a compile error on modern computers,
-        // x86_64 size_t is usually an unsigned long int, on the ESP8266 it is an unsigned int
-        LOGLN("    t %u", gradient.points[point].offset);
-    }
-
-    xSemaphoreTake(g_led_mutex, portMAX_DELAY);
-
-    leds_set_current_gradient(&gradient, 0);
-
-    xSemaphoreGive(g_led_mutex);
-
-    return (struct parse_error_t) { .error = NULL };
-}
-
-// receives HTTP GET requests on root
-static 
-esp_err_t on_http_get_root(httpd_req_t* request) {
-    // Error mewsages for cases of good and bad
-    static const char* response_ok = "OK!";
-
-    const char* response_msg = response_ok;
-
-    LOGLN("POST received on '/'.");
-
-    // buffer for query string
-    char* query_buffer;
-    size_t query_length = httpd_req_get_url_query_len(request) + 1;
-    struct parse_error_t result = { .error = NULL };
-
-    if(query_length > 1) {
-        query_buffer = malloc(query_length * sizeof(char));
-        if(httpd_req_get_url_query_str(request, query_buffer, query_length) == ESP_OK) {
-            LOGLN("Received query.");
-            result = parse_leds_query(query_buffer, query_length);
-        }
-    }
-
-    // an error was returned, pass it on to the API caller
-    if(result.error != NULL) {
-        httpd_resp_set_status(request, "400 Bad Request");
-        response_msg = result.error;
-    }
-
-    httpd_resp_send(request, response_msg, strlen(response_msg));
-
-    return ESP_OK;
-}
-httpd_uri_t get_root_uri = {
-    .uri="/",
-    .method=HTTP_GET,
-    .handler=&on_http_get_root,
-    .user_ctx = NULL
-};
-
-// Configure server and enable the http handler.
-static
-httpd_handle_t start_webserver(void) {
-    httpd_handle_t server = NULL;
-    httpd_config_t server_config = HTTPD_DEFAULT_CONFIG();
-
-    LOGLN("Starting HTTPd server ':%d'.", server_config.server_port);
-
-    if(httpd_start(&server, &server_config) == ESP_OK) {
-        httpd_register_uri_handler(server, &get_root_uri);
-        return server;
-    }
-
-    LOGLN("Failed to start HTTPd server.");
-    return NULL;
-}
-
-// Start an http server and store it's handle in g_http_server.
-static
-void server_init(void) {
-    g_http_server = start_webserver();
-}
+void server_init();
 
 #endif // !_potion_party_server_h

main/shared.h

@@ -7,10 +7,7 @@
 #ifndef _shared_h
 #define _shared_h
 
-#include <stdio.h>
-#include <string.h>
-#include <esp_wifi.h>
-#include "esp_system.h"
+#include <stdint.h>
 
 // wifi configuration
 #define SSID "ESP8266"
@@ -36,4 +33,15 @@ int clamp(int x, int mi, int ma) {
 
 #define GLOBAL(__a) (uint8_t)(__a|0xE0)
 
+typedef struct Result {
+    uint8_t is_ok;
+    union {
+        void* ok;
+        const char* error;
+    };
+} Result;
+
+#define PARSE_ERR(__err) (Result){.is_ok=0,.error=__err}
+#define PARSE_OK(__result) (Result){.is_ok=1,.ok=__result}
+
 #endif // !_shared_h